1. What is the plan? NASA wants to develop new technology to find an asteroid about 7 meters wide (about as wide as a swimming pool), send a spacecraft there carrying a large telescoping "bag," envelop it with the bag and maneuver the asteroid to a safe orbit around the moon for astronauts to visit and sample as early as 2021. See the slide show at left or NASA video below for a closer look at the plan, which as been under study for some time.

2. Why do it? Asteroids date back to the origins of the solar system. Exploring one would tell scientists a lot about how we got here. Eventually, we might want to mine asteroids for their precious minerals, although not the kind proposed for capture in this mission. And two recent asteroid close encounters -- one over Russia and one Earth flyby -- have raised the issue of defending the home planet from a potentially catastrophic collision like the one that killed the dinosaurs. Skills learned in this mission could help prevent such a collision.

3. Why not just go to back to the moon instead? A lot of people wonder the same thing. A group of powerful lawmakers, including Alabama's Rep. Robert Aderholt (R-Haleyville), are introducing legislation that would order NASA to do just that in about the same time frame. But beyond the "been there, done that" argument of President Obama, a return to the moon would take a lunar lander. NASA doesn't have one and getting a lander ready would be a challenge.

4. What are the challenges and risks? NASA has to find an asteroid that is just the right size and makeup (basically a dried up mudball so it would break up in the atmosphere if anything did go wrong). Then it has to build the spacecraft and telescoping bag to go get it. The agency has sent probes on close encounters with asteroids before, but actually grabbing one of these tumbling objects is something else again. NASA calls asteroids "uncooperative" in a an understatement.

5. Does Alabama have a piece of this rock? Two pieces, actually. An Atlas rocket built at United Launch Alliance in Decatur would be used to launch the spacecraft that goes after the asteroid, and the Marshall Space Flight Center in Huntsville is developing the booster part of the Space Launch System that will take astronauts to the asteroid. ULA, NASA and NASA's contractors employ thousands of skilled aerospace workers and support private businesses in Alabama.(Follow me on Twitter @leeroop)